In a log-structured filesystem, data is written sequentially in a temporal order to a circular buffer called a log. The physical storage for such a filesystem could be coming from one or more block based devices and/or object based storage. Some existing storage systems offer replication at the physical storage level for disaster recovery purposes. However, the physical replication logic in such systems does not have the knowledge of the temporal ordering that a log-structured filesystem needs to operate properly. This could lead to out-of-order writes on the replica, breaking the log-structured semantics with respect to the filesystem data as well as the metadata.
There is a need, therefore, for an improved method, article of manufacture, and apparatus for recovery of lost or corrupted log-structured filesystems.